"Definite answer" has a meaning of precise or exact answer, but not always correct answer, as in "definite measurement". "Definitive answer" has a meaning of conclusive answer or final answer, as in "definitive diagnose" or "definitive verdict".

DEFINITE just means that it's a clear answer. EX: yes, no, 36, 1234 maple street, . etc. Answers that are NOT definite: Maybe, could be, we'll see, a few, somewhat, somewhere up north, etc.. DEFINATIVE means something like QUINTESSENTIAL. e.g. Einstein's treatise is the definative work on relativity.

The definite answer is more affirmative, and the definite answer is a bit vague.